Only two files are required: a configuration file and a launcher.
The configuration file should be placed under /etc/sysupgrade.conf by default. The
launcher is called sysupgrade. A sensible location for
this is /usr/local/sbin/sysupgrade. Every time the
launcher is run it will include the configuration file and then
download a new copy of the upgrade script from the web location
named by the SOURCE configuration variable. This
script will be placed under /usr/local/lib/sysupgrade.sh and then
executed. This ensures users will always have the latest version of
the upgrade program.
Please check configuration file /etc/sysupgrade.conf before using sysupgrade.
Using any plain text editor modify configuration file as suggested below before launching sysupgrade for the first time. I embedded many comments in the file to help you.
The most important variable is SOURCE which is the location of the last version of the update script. If you are concerned about executing script code downloaded from my web site for security reasons, you may want to change this to a local copy of the script, which can be updated and inspected manually for enhanced security. The local copy can reside on a local HTTP server:
readonly SOURCE="http://YOUR_SERVER_NAME/PATH/sysupgrade.sh"
or you can use a static local file simple by leaving this variable empty:
readonly SOURCE=""
This way no download will occur: the script named by the
SCRIPT configuration variable will be executed
unchanged. You must place a copy of this script manually there. By
default its path is /usr/local/lib/sysupgrade.sh.
Sysupgrade will save a transcript of the messagges printed on
your terminal when last executed to text file
/root/sysupgrade.typescript. I find this feature
useful because I don't want to wait and watch the terminal for the
entire usually slow update process. I simply inspect this file when
the upgrade has finished, before or after rebooting the system. If
you also want the typescript file to be automatically sent to an
help desk or system administrator or yourself in the event that
problems arise, set destination email in configuration variable
HDMAIL. Also don't forget to set the from field for
emails in HDMAILFROM and of course the SMTP server the
machine is allowed to use in HDMAILSMTP.
# sysupgrade
Its that simple :-)
Just remember the first time you edit a configuration file to
save a default version before by
appending the .bak-default suffix to the filename,
e.g.:
# cp filename.ext filename.ext.bak-default# vi filename.ext
The presence of a default file will allow sysupgrade to try to automatically merge your modifications when new versions of the configuration file are installed. Without a default file sysupgrade can't even know what you have changed from the old default version and will do nothing except for issuing a warning.